This invention relates to the field of corn plants, and more specifically to improved corn lines having improved nutrative content and to a method for producing such lines.
Corn is the major crop on the cultivated land of the United States, where over 70 million acres were planted in 1995. U.S. corn production, accounting for about half of the world""s annual production, added over $23.5 billion of value to the American economy in 1995 as a raw material. Products derived from corn are used for human consumption, as raw material for industry and as raw material for the production of ethanol. The primary use of farmer-produced field corn is as livestock feed. This includes feed for hogs, beef cattle, dairy cows and poultry. About 60 percent of corn production is used for feeding livestock and poultry. A small increase in value to this 60% segment of the corn market, such as an increase of 10 cents per bushel, would increase its annual value by $480 million for an eight-billion bushel total corn harvest.
Human consumption of corn includes direct consumption of sweet corn, and consumption of processed-corn products such as cereals and snacks whose manufacture involves extruder cooking (e.g., Cheetos(trademark)), ground corn eaten as grits, corn meal and corn flour. Corn oil is also used as a high-grade cooking oil and salad oil, and in margarine. Corn is used in the production of some starches, sugars (e.g., fructose) and syrups. Another important use is in the production of sweeteners, such as corn syrup used in soft drinks.
Wet-milling and dry-milling processes also produce corn starch and corn flour that have applications in industry. These include use as elements of building materials, and in products used in the paper industry and in the manufacture of textiles and starches.
The seed of an inbred corn line, the plant produced by the inbred seed, hybrid seed produced from the crossing of the inbred to another inbred, the hybrid corn plant grown from said seed, and various parts of the inbred and hybrid corn plant can thus be utilized for human food, livestock feed, and as a raw material in industry.
According to Dr. Beryl B. Simpson of the University of Texas at Austin, there are three main theories on the origin of corn.
1. Tripartite Theory (Mangelsdorf):
The Tripartite Theory suggested in 1939 by Mangelsdorf (Mangelsdorf, P. C. and Reeves, R. G., 1939, The origin of Indian corn and its relatives, Texas Agric. Exp. Stn. Bull. 574:1-315) stated:
A. The ancestor of cultivated maize was both a popcorn and a pod corn. (This point has been borne out by the archaeological record.)
B. Teosinte is not the direct ancestor of maize but instead a taxon produced by hybridization of maize and Tripsacum.
This point in Mangelsdorf""s original tripartite theory is controverted by more recent findings indicating that annual teosinte resulted from a hybridization between maize and perennial teosinte Zea diploperennis. 
C. Many modern varieties of maize have undergone genetic introgression from teosinte or Tripsacum or, both either directly or via hybridization with other land races that hold different and distinct genetic blocks or DNA sequences. (Introgression involves incorporation of foreign genetic material into a line of breeding stock.) This notion of the role of introgression has greatly increased understanding of racial variation in maize.
2. xe2x80x9cTeosinte as an Ancestorxe2x80x9d Hypothesis (Galinat, Beadle)
In this theory, the female xe2x80x9ccobxe2x80x9d of teosinte became the cob of modern corn and the male inflorescence (tassel) of teosinte is the equivalent of the modern tassel of corn. Galinat has suggested that the differences between corn and teosinte can be reduced to three distinguishing features that separate the teosinte ear from that of a maize cob: a single spikelet per cupule versus two kernels in each cupule in maize, a two-ranked arrangement in teosinte (but appearing single by abortion in the xe2x80x9ccobxe2x80x9d) as opposed to many-ranked (multiple rows of kernels) in maize, and shattering rachis (cob) in teosinte vs. fused rachis (cob) in maize. The changes in teosinte that led to maize are a consequence of both lateral branch condensation (reduction) and genetic mutations that were favored by humans in the process of domestication.
Galinat has proposed a series of stages leading from teosinte to the primitive maize cob. He discovered them by studying the anatomical origin of the cupule in the maize cob and by breeding teosinte against a background of Nal-Tel corn. Further breeding of the F2 population with teosinte and Nal-Tel resulted in an assorted group of plants including potential ancestral forms. Doebley has recently demonstrated the numbers and locations of the genes responsible for the major differences between corn and teosinte. There are five major genes and some pleiotropic genes involved.
3. CSTT or Catastrophic Sexual Transmutation Theory (Iltis)
According to this theory devised by Hugh Iltis, the modern corn cob is a transformed male teosinte rachis. The socket for the male flower evolved into a cupule to provide support for two developing kernels. Each teosinte spikelet consists of a pair of a fertile and a sterile floret. In the process of sexual transformation, the sterile floret became sexual again, producing two kernels (two-ranked) in each cupule leading to an expressed two-ranked condition. The size of the cob can expand because the male tassel has numerous rachises holding the florets (teosinte fruits are single ranked and pressed to the single rachis). As each tassel branch becomes fertile a longer cob is possible. Furthermore, the initial cob should have four kernel rows as a result of the alternation of floral segments. If these twist around, then the row number increases as the ear becomes more compact. None of these morphological changes require new genes, merely a switch in the development patternxe2x80x94a switch that is sometimes seen in abnormal corn male tassels.
Recently Etis has modified his view of the xe2x80x9ctransformationxe2x80x9d of male into female inflorescences (still Catastrophic Sexual Transmutation Theory). However, John Doebley has genetic data that show which genes control the characters that cause the differences in the ears of teosinte and maize.
Modern commercial corn is generally a hybrid maize plant (Zea mays L.) grown from seed of a cross of two inbred lines. Other sources of corn have been neglected because of the vastly superior yield that has developed over time by various breeding programs. Typically, a modern maize inbred line is self-pollinated, sib-crossed, and/or back-crossed in order to concentrate reliably inheritable characteristics into that inbred line.
According to U.S. Pat. No. 5,728,922 issued Mar. 17, 1998 to Albert R. Hornbrook (which is incorporated herein by reference), maize is a highly variable species. For hundreds of years, maize breeding consisted of isolation and selection of open-pollinated varieties. Native Americans developed many different varieties since the domestication of maize in prehistory. Theories about such domestication are described above. During the course of the nineteenth century, North American farmers and seedsmen developed a wide array of open-pollinated varieties, many of which resulted from an intentional or an accidental cross between two very different types of maize: the Southern Dents, which resemble varieties still grown in Mexico, and the Northern Flints, which seem to have moved from the Guatemalan highlands into the northerly parts of the United States and into Canada. The open-pollinated varieties which were developed during this time were maintained by selection of desirable ears from within the variety for use as foundation seed stock. The only pollination control which was practiced to generate the seed was isolation of the seed crop from pollen from other varieties. Experimentation with inbreeding in open-pollinated varieties showed that it invariably led to a marked reduction in plant vigor and stature, as well as in productivity.
In the early twentieth century, researchers discovered that vigor was restored when an inbred line from an open-pollinated variety was crossed to another, usually unrelated, inbred line, and that the resulting hybrids were not only more uniform than open-pollinated varieties, but in many cases were more productive as well. Many of the inbreds developed from open-pollinated varieties were remarkably unproductive, however, which made F1 seed quite expensive to produce in any volume. By the 1930""s seedsmen were offering four-way (or double) crosses to growers. These consisted of a cross between two single crosses, which in turn were each crosses between two inbred lines. In this way, only a small quantity of single-cross seed was required, and the seed sold to growers was produced on F1 hybrids. Four-way crosses dominated the seed industry until the late 1950""s, when three-way crosses were offered to growers, consisting of seed produced on a single-cross hybrid with an inbred line as the pollinator. Through the efforts of public and private maize breeders, inbred lines were selected to be more productive and vigorous than the earlier selections from the open-pollinated varieties, and by the early 1970""s, single-cross seed was readily available to growers. Presently, the overwhelming majority of hybrid corn seed sold in the United States is single-cross maize seed.
Among the major reasons for the economic importance of corn and the large acreages planted with the crop are the successful hybridization of the maize plant and the continued improvement, by researchers, of the genetic stock that is used to produce the seed grown by farmers. This process has been on-going since its beginning in the early part of the century. The average bushel-per-acre yield for the American farmer has gone from around 30 in the middle of the 1930""s (before hybrids became dominant) to the present average of close to 120. While not all of this four-fold increase can be attributed to genetic improvement (availability of relatively cheap nitrogen and improvements in farming practices are two other components), a good share of it can.
The physical structure of the maize plant provides the maize breeder with opportunities either to cross a plant with another plant or to self-pollinate a given plant. Since the male inflorescence (the tassel) and the female inflorescence (the ear) are physically separated from each other on the plant, the breeder has the ability to mate plants as desired with relative ease. Similar physical manipulations are used both for cross-pollinating and for self-pollinating a maize plant. The silks (stigmae of maize female florets) are protected from pollination until pollen is collected from the male inflorescence. For cross-pollination, pollen from one plant is distributed on the silks of another plant, while for self-pollination, pollen from a plant is distributed on silks of the same plant. Sib-pollination is a type of cross-pollination in which both plants are closely related genetically. Cross-pollinating and self-pollinating techniques are used in the development of inbreds which, when crossed, produce seed of commercially available maize hybrids. Self-pollination and sib-pollination increase the level of inbreeding in progeny plants, leading to fixation of alleles.
With continued inbreeding comes a large reduction in vigor and productivity. This phenomenon is know as inbreeding depression. The progeny from the crossing of two inbred lines is a first-generation (F1) hybrid, which has better productivity and agronomic characteristics than either of the inbred parents. This phenomenon is called hybrid vigor or heterosis. Heterosis is reduced markedly in succeeding generations (F2, F3, etc.), making it economically justifiable for the farmer to obtain F1 seed each year for planting. As a result, the hybrid maize seed industry benefits both farmers and producers of hybrid maize seed.
The method of hybridization in maize first involves the development of inbred lines. Inbred lines are commonly developed through some variation of pedigree breeding, wherein the plant breeder maintains the identity of each new line throughout the inbreeding process. To initiate the pedigree breeding process, the breeder may make an F1 cross between two existing inbred lines which complement each other for traits for which improvement is desired, and which cross well with other inbreds from other genetic backgrounds to make commercial hybrids. The F1 is selfed to provide F2 seed (also called the S1 seed), which is planted and selfed to produce the S2 or F3 generation. S2 lines are planted ear-to-row, and self-pollinations are made within individual rows. Rows which do not provide a desirable phenotype are discarded. Selected ears are planted ear-to-row, and this process repeats until substantial homozygosity is attained, usually by the S6 or S7 generation. Once homozygosity is attained, the inbred can be maintained in open-pollinated isolations. At some point during the breeding process, the inbred lines are crossed to a tester inbred line of a different genetic background and evaluated in replicated yield tests. Lines that result in inferior crosses with the tester inbred line are discarded.
Maize breeders, in general, structure their efforts to take advantage of known heterotic patterns; that is, they use their knowledge of which inbreds make good hybrids with which other inbreds, and they ensure that genetic material from these heterotic pools does not cross over into opposing pools. A highly successful heterotic pattern in the United States Corn-Belt has been to use lines from a population known as Iowa Stiff Stalk Synthetic crossed with lines having more or less of a Lancaster background to provide hybrids for growers (Lancaster was a relatively unimportant open-pollinated variety, until it was discovered in the early years of inbred/hybrid development that it provided an outstanding source of lines with good general combining ability). Other heterotic patterns have also been developed, primarily for the northern and southern regions of the United States. Breeders have understandably been reluctant to use competitive private company hybrids as source material, because, in such instances, usually it will not be known where derived lines fit in a heterotic pattern (Hallauer et al., xe2x80x9cCorn Breedingxe2x80x9d, Corn and Corn Improvement pp. 463-564, (1988)). As well, using competitors"" hybrids as source germplasm risks the dispersal of existing heterotic patterns: many breeders feel that introducing, for example, Lancaster material into an Iowa Stiff Stalk background would lessen their ability to develop lines which could be crossed to Lancaster-derived inbreds. Unless it is known that a competitor""s hybrid was genetically distinct from a breeder""s own material, it is considered to be a more risky approach to improvement of a heterotic pool than utilizing known material.
While a maize breeder might anticipate that a source population is capable of providing a certain degree of variation, that variation first has actually to occur, and then to be identified by the breeder. Most variants are expected to fall between the parental values for any given trait; only very exceptional individuals will exceed the better parent (or be worse than the worse parent) for a trait. This is especially true when a trait is determined by a large number of genes, each having a relatively small effect on the trait. Most traits of interest to the maize breeder, including productivity, maturity, and stalk and root quality, are such traits. To complicate matters further, high negative correlations occur in maize between productivity, maturity, and stalk quality. A breeder may be able to improve yield, but at the expense of stalk quality or later maturity. The occurrence of an individual with a combination of superior traits is very rare. Even if the individual does occur in a sample of the source population, the breeder often lacks the resources required to identify that individual. Traits of low heritability, such as productivity, must be evaluated in several locations to be accurately evaluated. Only a very limited number of genotypes can be tested because of constraints upon resources. Thus, a breeder may miss the desired individual, simply because he cannot evaluate all genotypes produced by the source population.
A valuable lesson was learned years ago about the expectation of the success of progeny improvement methods. The inbred Wf9 was developed in Indiana, and released to seed growers in the mid-1930""s. Despite having several agronomic deficiencies, it became the most widely used inbred during the double-cross era of maize seed production. It naturally became the basis for numerous public improvement projects. Despite having abundant resources applied to the objective of developing an improved Wf9, no inbred from the public sector with a Wf9 background ever supplanted Wf9 in seed-production fields. A similar story can be told about A632, at one time the predominant seed line for Northern Corn-Belt hybrids. Many public breeders tried to improve on A632, but no A632-derived line from the public sector achieved the prominence of A632, and it was eventually supplanted by a completely unrelated inbred. More recently, B73 improvement programs have been tried, and a number of B73-derived progenies have been commercially accepted. Many modern stiff-stalk commercial lines are improved B73""s, at least for pest resistance.
The objective of a plant breeder when developing a new inbred line of maize is to combine the highest number of desirable alleles into a single isolate as possible. No parent line contains all desirable alleles at all loci, and the breeder hopes to introgress a higher frequency of favorable alleles into resulting progenies. However, with the current state of the art, a breeder is generally not able to define which allele at any given locus is desirable, and for most traits of interest, he does not have information about which genetic loci are involved in influencing the trait. His primary tool to measure the genotypes of progenies is phenotypic evaluation. The phenotype of a plant is influenced both by its genotype and the environment in which it is grown, so the phenotypic measure of a plant is only an indirect measure of its genotype. When environmental effects are large relative to the genotypic effects, it is said that the trait has low heritability. The breeder must evaluate traits of low heritability in many different environments in order to be reasonably sure that he has an accurate estimate of the genotypic effect. Productivity of marketable grain is such a trait, according to years of breeding experience and numerous scientific publications.
The requirement of evaluating genotypes in different environments places serious restraints on the maize breeder in terms of the number of genotypes the breeder will be able to evaluate. The large number of possible genotypes, coupled with the small sample size from a segregating population, make it uncertain that a breeder will be able to invent a new maize inbred line which is a measurable improvement over its parents. The invention of new inbred lines and of new hybrids is extremely important to the companies in the hybrid seed maize industry that have investments in research. Much effort is given to the research and development of these inbreds and hybrids. The breeding and selection of inbred lines involves many years of inbreeding, skilled selection, correct statistical testing, and decision making.
According to U.S. Pat. No. 5,330,547 issued Jul. 19, 1994 to Mary W. Eubanks (which is incorporated herein by reference), maize is a monoecious grass, i.e., it has separate male and female flowers. The staminate, i.e., pollen-producing, flowers are produced in the tassel and the pistillate or female flowers are produced on the shoot. Pollination is accomplished by the transfer of pollen from the tassel to the silks. Since maize is naturally cross-pollinated, controlled pollination, in which pollen collected from the tassel of one plant is transferred by hand to the silks of another plant, is a technique used in maize breeding. The steps involved in making controlled crosses and self-pollinations in maize are as follows: (1) the ear emerging from the leaf shoot is covered with an ear shoot bag one or two days before the silks emerge to prevent pollination; (2) on the day before making a pollination, the ear shoot bag is removed momentarily to cut back the silks, then is immediately placed back over the ear; (3) on the day before making a pollination, the tassel is covered with a tassel bag to collect pollen; (3) on the day of pollination, the tassel bag with the desired pollen is carried to the plant for crossing, the ear shoot bag is removed and the pollen dusted on the silk brush, the tassel bag is then immediately fastened in place over the shoot to protect the developing ear.
Wild relatives of crop plants are an important source of genetic diversity and genes well adapted to many different stresses. The wild relatives of maize include annual teosinte (Zea mexicana), perennial teosinte and Tripsacum. Tripsacum is a more distant relative of maize with a different haploid chromosome number (n=18). The progeny of (maize X Tripsacum) obtained by artificial methods are thought to be all male sterile and have limited female fertility when pollinated by maize pollen. Cytogenetic studies of maize-Tripsacum hybrids show partial chromosome pairing and homology between segments of Tripsacum and maize chromosomes (Maguire, M. P., 1961, Evolution 15:394-400; Maguire, M. P., 1963, Genetics 48:1185-1194; Chaganti, R. S. K., 1965, Bussey Inst. Harv. Univ., 93p.; Galinat, W. C., 1974, Evolution 27:644-655). In spite of strong cross-incompatibility, the fact that maize and Tripsacum chromosomes can occasionally pair with one another enables limited transfer of Tripsacum genes into maize.
Successful introgression of Tripsacum genetic material into maize heretofore has required years of complicated, high-risk breeding programs that involve many backcross generations to stabilize desirable Tripsacum genes in maize. According to Kindiger and Beckett: xe2x80x9cTripsacum may be expected to contain valuable agronomic characters . . . that could be exploited for the overall improvement of maize. An effective procedure to transfer Tripsacum germ plasm into maize has been needed by maize breeders and geneticists for many yearsxe2x80x9d (1990, p. 495). Beneficial traits that may be derived from Tripsacum include heat and drought tolerance (Reeves, R. G. and Bockholt, A. J., 1964, Crop Sci. 4:7-10), elements of apomixis, increased heterosis (Reeves and Bockholt 1964; Cohen, J. I. and Galinat, W. C., 1984, Crop. Sci. 24:1011-1015), resistance to corn root worm (Branson, T. F., 1971, Ann. Entomol. Soc. Am. 64:861-863), corn leaf aphid, northern and southern leaf blight, common rust, anthracnose, fusarium stalk rot and Stewart""s bacterial blight (Berquist, R. R., 1981, Sci. Monogr. Univ. Wyo. Agric. Exp. Stn., The Station 71:518-520; de Wet, J. M. J., 1979, Broadening the Genetic base of crops, PUDOC, Center for Agricultural Publishing and Documentation, 203-210, Zevon, A. C. and van Harten, A. M. (eds.), Wageningen, Netherlands). Plant breeders acknowledge Tripsacum has significant potential for improving corn by expanding its genetic diversity (Cohen, J. I. and Galinat, W. C., 1984; Poehlman, J. M., 1987, Breeding Field Crops, 3rd Ed., AVI Pub. Co., 451-453). The limited fertility of maize-Tripsacum hybrids presents a significant biological barrier to gene flow between these species.
Zea mays X Tripsacum plants have unreduced gametes with 28 chromosomes, one set of 10 Zea chromosomes and one set of 18 Tripsacum chromosomes. There has been one report of a successful reciprocal cross of Tripsacum pollinated by maize in which embryo culture techniques were used to bring the embryo to maturity. The plants were sterile (Farquharson 1957). This (Tripsacura X maize) plant was employed by Branson and Guss (1972) in tests for rootworm resistance in maize-Tripsacum hybrids. When the (maize X Tripsacura) hybrid has been crossed with either annual teosinte or diploperennis, a trigenomic hybrid has been produced that has a total of 38 chromosomes; 10 from maize, 18 from Tripsacum and 10 from teosinte. The resulting trigenomic plants were all male sterile and had a high degree of female infertility.
What are needed are corn lines having compositions of protein, oil, and starch that are significantly different from the compositions found in conventional corn lines.
According to the invention, there are provided novel introgressed corn lines containing genetic material from Tripsacum dactyloides L., wherein, in the breeding procedure, selections have been made both for yield, kernel size, stalk strength, pest resistance, and other maize-like qualities, as well as selecting for desirable new traits, such as high protein content, high oil content, high oleic acid content, high or low saturated oil content, and/or starch having unique thermal characteristics. The desirable new traits are contributed by the introgression of Tripsacum genetic material into corn lines and the selection process.
According to one embodiment of the invention, there is provided a novel inbred (maize) corn line, designated GC, that provides higher protein content than conventional corn lines, higher oil content than conventional corn lines, or both higher protein and higher oil than conventional corn lines. (In the present description, the general designation xe2x80x9cGCxe2x80x9d followed by xe2x80x9c#xe2x80x9d and a four-digit plant line number will refer to any of the specific corn lines that are listed in the next paragraph.) This invention thus relates to the seeds of a GC inbred maize line, to the plants of a GC inbred maize line, to the pollen of a GC inbred maize line, and to methods for producing a maize plant produced by crossing a GC inbred line with itself, another GC line or another maize line. This invention further relates to hybrid maize seeds and plants produced by crossing a GC inbred line with either another GC line or with another maize line.
According to one embodiment of the invention, there are provided corn lines based on introgressions between and among selected recovered lines of maizexTripsacum material (said recovered lines including #5S1, #13S1, #15S1), and publicly available inbred lines including A632, B73, W153R, and Mo17. At least some of the selections were based initially on high oleic-acid content and high saturated-fatty-acid content.
Another aspect of the present invention provides seed of high-protein inbred corn lines designated GC#3892, GC#3805, GC#3978, GC#3728, GC#3963, GC#3642, GC#3781, or GC#3663, high-oil inbred corn lines designated GC#4066, GC#3886, GC#3831, GC#3833, GC#3641, GC#3839, GC#3822, GC#3930, GC#3969, GC#3696, GC#3829, GC#3713, GC#4037, GC#3700, GC#3901, GC#3809, GC#3689, GC#3640, GC#3723, GC#3821, GC#3892, GC#3697, GC#4053, GC#3711, GC#3712, GC#3823, GC#3694, GC#3838, GC#3717, GC#3687, GC#3968, GC#4151, GC#3941, GC#3695, GC#3806, GC#3926, GC#3896, GC#3808, GC#3927, GC#3719, or GC#3810, or high-protein-and high-oil inbred corn lines designated GC#3847, GC#3763, GC#3913, GC#3753, GC#3820, GC#3905, GC#3815, GC#3911, GC#3646, GC#3951, GC#4026, GC#3692, GC#3929, GC#3978, GC#3807, GC#3643, GC#4090, GC#3961, GC#3922, GC#3631, GC#3812, GC#3716, GC#3691, GC#3674, GC#3714, GC#4020, GC#3636, GC#1330, GC#3747, GC#3933, GC#3932, GC#3924, GC#3762, GC#3971, GC#3904, GC#3956, GC#4158, GC#3964, GC#4030, GC#4054, or GC#1324 (collectively, xe2x80x9cGC inbred maize linesxe2x80x9d). In one embodiment, the present invention provides a xe2x80x9cfirstxe2x80x9d corn plant produced by said seed or regenerable parts of said seed (the term xe2x80x9cfirstxe2x80x9d corn plant refers to an arbitrary plant produced by said seed or regenerable parts of said seed).
In another embodiment, the present invention provides seed of the first corn plant. In yet another embodiment, the present invention provides pollen of the first corn plant. In one such embodiment, the present invention provides seed of a corn plant pollinated by such pollen.
In another embodiment, the present invention provides an ovule of the first corn plant produced by said seed or regenerable parts of said seed.
In yet another embodiment, the present invention provides a corn plant having all the physiological and morphological characteristics of the first corn plant.
Another aspect of the present invention provides a tissue culture of regenerable cells, wherein the cells include genetic material derived, in whole or in part, from high-protein and/or high-oil inbred corn lines of the invention as designated above, and wherein the cells are regenerable into plants having the morphological and physiological characteristics of the respective GC inbred corn lines.
In yet another embodiment, the present invention provides a tissue culture comprising cultured cells derived, in whole or in part, from a plant part of a plant of the present invention, wherein the plant part is selected from the group consisting of leaves, roots, root tips, root hairs, anthers, pistils, stamens, pollen, ovules, flowers, seeds, embryos, stems, buds, cotyledons, hypocotyls, cells and protoplasts. In one such embodiment, a corn plant is regenerated from the tissue culture, the corn plant having all the morphological and physiological characteristics of the respective GC inbred corn lines.
In yet another embodiment, the present invention provides a method for producing high-protein content or high-oil content or high-protein and high-oil content corn seed comprising the step: crossing a first parent corn plant with a second parent corn plant and harvesting resultant first-generation (F1) hybrid corn seed, wherein said first or second parent corn plant is the first corn plant described above.
Another aspect of the present invention provides a method for breeding and selecting corn including the steps of: (a) introgressing plants of a corn line with plants of genus Tripsacum, to obtain genetic material; (b) growing corn plants from the genetic material resulting from the introgressing step of step (a) to obtain seeds; and (c) selecting from among the seed of the corn plants of step (b) those seeds having superior protein content or oil content or both.
In one such embodiment, the method further includes the step of: (d) creating an inbred corn line derived from the selected seeds of step (c). In another such embodiment, the method further includes the step of: (e) crossing the inbred corn line with another inbred corn line to obtain hybrid seeds. In yet another such embodiment, the method further includes the step of: (f) generating plants from the hybrid seeds resulting from step (e). In still another such embodiment, the method further includes the step of: (g) generating a tissue culture of regenerable cells from genetic material derived from the plants resulting from step (b), said tissue culture derived, in whole or in part, from a plant part selected from the group consisting of leaves, roots, root tips, root hairs, anthers, pistils, stamens, pollen, ovules, flowers, seeds, embryos, stems, buds, cotyledons, hypocotyls, cells and protoplasts.
Yet another aspect of the present invention provides seed of a corn variety, said variety having greater than or equal to about 10% protein at 0% moisture content. In one embodiment, the seed have greater than or equal to about 15% protein at 0% moisture content, and greater than or equal to about 12% protein at 15% moisture content. In another embodiment, the seed have greater than or equal to about 17% protein at 0% moisture content, and greater than or equal to about 14% protein at 15% moisture content. In yet another embodiment, the seed have greater than or equal to about 4% oil at 0% moisture content, and greater than or equal to about 3.5% oil at 15% moisture content.
In one such embodiment, said corn variety has genetic material derived from a plant of genus Tripsacum. In another such embodiment, the corn variety has genetic material derived from a plant of Tripsacum dactyloides L. 
Another aspect of the present invention provides a second corn plant, or its parts, produced by such seed or regenerable parts of said seed. In another embodiment, the present invention provides seed of the second corn plant. In yet another embodiment, the present invention provides pollen of the second corn plant. In still another embodiment, the present invention provides seed of a corn plant pollinated by the pollen of the second corn plant.
A. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram.
B. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, wherein said seed is the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a parent from a second corn line.
C. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, wherein said seed is the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a parent from a second corn line, wherein said oleic acid content is about 60% or greater.
D. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, wherein said seed is the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a parent from a second corn line, wherein said oleic acid content is about 60% or greater, wherein said oleic acid content is about 65% or greater.
E. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, wherein said seed is the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a parent from a second corn line, wherein said oleic acid content is about 60% or greater, wherein said oleic acid content is about 70% or greater.
F. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, wherein said oleic acid content is between about 60% and about 70%.
G. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, said seed being the product of a corn plant having the characteristics of a GC inbred corn line.
I. In one embodiment, the present invention provides a corn seed comprising a yellow seed coat and having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and for said yellow seed coat and (B) a second parent, wherein said first parent comprises germplasm encoding said oleic acid content and said second parent comprises a genetic determinant for yellow or white seed color.
J. In one embodiment, the present invention provides a corn seed comprising a yellow seed coat and having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and for said yellow seed coat and (B) a second parent, wherein said first parent comprises germplasm encoding said oleic acid content and said second parent comprises a genetic determinant for white seed color, wherein said first parent is from a GC inbred corn line.
K. In one embodiment, the present invention provides a corn seed comprising a yellow seed coat and having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and for said yellow seed coat and (B) a second parent, wherein said first parent comprises germplasm encoding said oleic acid content and said second parent comprises a genetic determinant for white seed color, said seed being the product of a corn plant having the characteristics of a line selected from the group consisting of a GC inbred corn line and a corn line based on a GC inbred corn line.
L. In one embodiment, the present invention provides a corn seed comprising a yellow seed coat and having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and for said yellow seed coat and (B) a second parent, wherein said first parent comprises germplasm encoding said oleic acid content and said second parent comprises a genetic determinant for white seed color, said seed being the product of a corn plant having the characteristics of a line selected from the group consisting of a GC inbred corn line and a corn-line based on a GC inbred corn line.
M. In one embodiment, the present invention provides a corn seed comprising a white seed coat and having oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a second parent.
N. In one embodiment, the present invention provides a corn seed comprising a white seed coat and having oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a second parent, wherein one of said first and second parents comprises a genetic determinant for white seed color.
O. In one embodiment, the present invention provides a corn seed comprising a white seed coat and having oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seed, said seed being the product of a cross between (A) a first parent from a corn line that is true-breeding for said oleic acid content and (B) a second parent, wherein one of said first and second parents comprises a genetic determinant for white seed color, wherein said second parent is from a corn line that is true-breeding for said oleic acid content.
P. In one embodiment, the present invention provides a corn plant that produces seeds that have an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and that have a weight per seed of greater than about 0.15 gram.
Q. In one embodiment, the present invention provides a corn plant that produces seeds that have an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and that have a weight per seed of greater than about 0.15 gram, wherein said oleic acid content is between about 60% and about 70%.
R. In one embodiment, the present invention provides a method for producing a yellow-coated corn seed having an oleic acid content of approximately 50% or greater by weight, comprising the step of crossing (A) a first parent that comprises Tripsacum germplasm encoding said oleic acid content with (B) a second parent that comprises a genetic determinant for yellow seed color.
S. In one embodiment, the present invention provides a method for producing a yellow-coated corn seed having an oleic acid content of approximately 50% or greater by weight, comprising the step of crossing (A) a first parent that comprises Tripsacum germplasm encoding said oleic acid content with (B) a second parent that comprises a genetic determinant for yellow seed color, wherein both of said first and second parents are true-breeding for said yellow seed color.
T. In one embodiment, the present invention provides a method for producing a white-coated corn seed having an oleic acid content of approximately 50% or greater by weight, comprising the step of crossing (A) a first parent that yields white seed with (B) a second parent that comprises Tripsacum germplasm encoding, and that is true-breeding for, said oleic acid content.
U. In one embodiment, the present invention provides a product consisting of a substantially homogeneous assemblage of corn seeds that has an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seeds.
V. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line.
W. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line, wherein said oleic acid content is about 60% or greater.
X. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line, wherein said oleic acid content is about 65% or greater.
Y. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line, wherein said oleic acid content is about 70% or greater.
Z. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line, wherein said seeds each comprise a white seed coat.
AA. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line, wherein said seeds each comprise a yellow seed coat.
BB. In one embodiment, the present invention provides a corn-seed product consisting of a substantially homogeneous assemblage of corn seeds that have an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said seeds being the product of a cross between (A) parents from a first corn line that is true-breeding for said oleic acid content and (B) parents from a second corn line, wherein said corn seeds, when grown under temperature conditions ranging from those of a northern climate to those of a southern climate, yield plants that produce seeds displaying a variation in said oleic acid content of about 4 to 5% by weight or less.
CC. In one embodiment, the present invention provides a corn line consisting of a substantially uniform population of Zea Mays L. plants that produce seeds having an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said line being true-breeding for said oleic acid content.
DD. In one embodiment, the present invention provides a corn line consisting of a substantially uniform population of Zea Mays L. plants that produce seeds having an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said line being true-breeding for said oleic acid content, wherein said oleic acid content is about 60% or greater.
EE. In one embodiment, the present invention provides a corn line consisting of a substantially uniform population of Zea Mays L. plants that produce seeds having an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said line being true-breeding for said oleic acid content, wherein said oleic acid content is about 65% or greater.
FF. In one embodiment, the present invention provides a corn line consisting of a substantially uniform population of Zea Mays L. plants that produce seeds having an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said line being true-breeding for said oleic acid content, wherein said oleic acid content is about 70% or greater.
GG. In one embodiment, the present invention provides a corn line consisting of a substantially uniform population of Zea Mays L. plants that produce seeds having an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said line being true-breeding for said oleic acid content, wherein said seeds each comprise a white seed coat.
HH. In one embodiment, the present invention provides a corn line consisting of a substantially uniform population of Zea Mays L. plants that produce seeds having an oleic acid content of approximately 60% or greater, relative to the total fatty acid content of said seeds, said line being true-breeding for said oleic acid content, wherein said seeds each comprise a yellow seed coat.
II. In one embodiment, the present invention provides a corn seed having an oleic acid content of approximately 50% or greater, relative to the total fatty acid content of said seed, and having a weight per seed of greater than about 0.15 gram, wherein said corn seed is true-breeding for said oleic acid content.